All of the units you've listed are incredibly capable decks. The top three I have no direct experience with and as a result cannot comment on them with any degree of authority.

The two Kenwood eXcelon units you listed are both very, very nice. I've not seen the X990 in person yet but on paper the only advantage it offers over the XXV-01D Anniversary unit is the use of Wolfson digital-to-analog converters rather than the Burr-Brown units in the older eXcelon decks. I cannot imagine that there is enough of a difference in SQ to justify over $150 difference in purchase price and as the XXV-01D is an Anniversary edition deck I would imagine over time it will likely hold its resale value more strongly than will the X990.

But overall I cannot see you being unhappy with any of them so go with the one that best suits your specific needs and can be had at the best price. :D